Quantitative Comparison of Yttrium-90 (⁹⁰ Y)-Microspheres and Technetium-99m (^99m Tc)-Macroaggregated Albumin SPECT Images for Planning ⁹⁰ Y Therapy of Liver Cancer

Abstract

253The Spearman's rank correlation thus appears to be more reliable than the image distance for assessing the correlation of the 90 Y and MAA images.

Semi-Quantitative Analysis of Post-Transarterial Radioembolization 90Y Microsphere Positron Emission Tomography Combined with Computed Tomography (PET/CT) Images in Advanced Liver Malignancy: Comparison With 99mTc Macroaggregated Albumin (MAA) Single Photon Emission Computed Tomography (SPECT)

“…Moreover, 99m Tc MAA images are not considered to be ideal method to predict the actual distribution of the 90 Y microspheres. Recent reports have postulated that there is a discordance between 99m Tc MAA and 90 Y microsphere bremsstrahlung SPECT [12,28,29].…”

“…Many reports have suggested the correlation of 99m Tc MAA dosimetry and intraoperative estimation of radiation doses [6][7][8][9][10][11]. After the injection of the microsphere, postembolization evaluation for the distribution of 90 Y microspheres is essential to predict possible complications and treatment response [12]. Bremsstrahlung imaging and/or SPECT of 90 Y microspheres is useful not only for the evaluation of posttreatment distribution of microspheres in the liver target volume, but also for the evaluation of possible extrahepatic spillage.…”

Multiagent imaging of liver tumors with reference to intra-arterial radioembolization

“…The number of albumin particles is significantly lower than the number of injected 90 Y-microspheres (0.1-0.2 millions of MAA versus 30-60 millions of resin and 4-5 millions of glass particles), and a similar pattern is seen with the density (1.1 versus 1.6 g/mL for resin and 3.3 g/mL for glass particles). These features might explain why the mismatch problem seems to be more serious for embolic resin spheres [41][42][43]. The literature is controversial, however, since Kao et al [44], for instance, found excellent correspondence between 99m Tc-MAA SPECT and 90 Y PET dosimetry (median relative error 3.8 %).…”

“…The absence of a photopeak prohibits the use of simple window-based scatter rejection, scatter correction, and attenuation correction techniques, and penetration of highenergy photons through the collimator septa leads to further loss of image contras. Several reconstruction algorithms and imaging protocols have been proposed to overcome these technical limitations [41,45]. The use of pinhole collimators seems to result in better contrast recovery coefficients compared with those obtained with parallel-hole collimators.…”

A review of 3D image-based dosimetry, technical considerations and emerging perspectives in 90Y microsphere therapy

“…Thus existing differences in flow between metastatic lesions of variable size are likely to be exaggerated on MAA imaging when compared to MS imaging. In recent work, the visual correlation between co-registered MAA distribution and RMS distribution for 20 patients with hepatic metastases ranged from high to very poor, with a mean Spearman rank correlation of 0.65 [74]. A study of RMS in 39 patients (with both HCC & metastatic lesions) segmented the liver into segments, and showed that for 68% of all segments (n=225), a difference of >10% between MAA and MS activity distribution was found, and that in every procedure at least 1 segment showed a >10% difference [58].…”